Are the same words spelt differently between Québécois French and Parisian French?
Words that are shared by the French used by Quebecois and Parisians are usually not spelled differently.
Having answered the question, I will provide some other details that you may find helpful.
Many of the differences in the usage of French words in this context are found in speech and pronunciation. There are however, other important differences.
Constructions of sentences can differ between the two and they also use slightly different lexicons.
Here is an example of a lexical difference:
In France, the word that is most used for 'email' is 'mail'.
Example sentence: "Je vais envoyer un mail"
A word for this arose from Quebec: 'courriel'. This word is now considered an acceptable synonym in French, although depending on the location you will hear either.
Example sentence: "Je vais envoyer un courriel"
Here is a an example of difference in construction, lexicon, and pronunciation:
To express "I am here", there are different ways to do this and if you are in Paris, Quebec, and even in Acadian regions in New Brunswick. Let me explain....
In Paris one would most likely say: "Je suis là" or "Je suis ici", the former being the preferred.
In Quebec one would most likely say: "Je suis ici" and less often: "Je suis là".
In New Brunswick you will almost always hear: "Je suis ici". However! It is important to note that in New Brunswick, the pronunciation of 'ici' is quite different! 'Ici' in the Acadian variety of French is pronounced with a 't' sound on the end (ih-SIT).